A mobile telephone comprises a number of elements dedicated to various functions offered to users. The main elements at present are:                a keypad enabling users to communicate data to their telephones;        a screen enabling telephones to communicate with their users;        a microphone and a loudspeaker providing voice communication;        a radio communication element (for example of the GSM type) providing long-distance communication over the network of the telecommunications carrier;        a memory for storing data specific to the operation of the telephone or personal to the user;        a subscriber smart card (for example a SIM or USIM card), which remains the property of the telecommunications carrier with whom the user has a contract and provides cryptography functions enabling in particular mutual authentication with the network;        various “camera” type peripherals or Bluetooth™ Irda™, Wifi™, etc. communication ports;        an operating system (for example Windows Mobile™) and associated electronics (processor means) for managing all elements of the mobile device and providing communication between them;        possibly a removable memory card or MMC (multimedia memory card) with a format that varies as a function of the terminal (SD, miniSD, etc.).        
Some mobile telephones have recently been provided with an ISO 14443 family contactless smart card type near-field communication module. This module is a contactless microchip comprising a set of components that is integrated into the mobile telephone, one of which components provides security component functions (secret data necessary for a contactless transaction, authentication, encryption, signature, etc.), for example the Philips™ Smart MX circuit. Note that some or all of this microchip (in particular the NFC security component) can equally be integrated into a removable memory card if the telephone incorporates one. The contactless microchip uses the NFC or ISO 14443 technology.
NFC microchips include an antenna and an electronic circuit and the most sophisticated examples can transmit, receive and process information via the antenna, which is also used to transmit the power needed by the microchip. NFC microchips include a security component able to store data, to control access thereto and broadcasting thereof, and to perform algorithm-based functions (encryption, identification/authentication, signature). To enable a very short response time (less than 300 milliseconds (ms) or even 140 ms), it is necessary for the NFC microchip, which processes the data exchanged on the near-field radio-frequency channel, to be connected directly to the antenna.
A mobile telephone with an NFC microchip can perform a number of operations such as secure electronic payment, opening doors or barriers, facilitating downloading of multimedia contents (tunes, videos, etc.). To perform these operations, the user places a mobile telephone including an NFC microchip near an NFC microchip reader associated with the corresponding device (payment terminal, access point, etc.).
To enable the user to consult/manage some of the data stored in the NFC microchip (for example to display on the screen of the telephone information contained in the NFC microchip such as the number of payment tickets remaining or to activate/deactivate a particular function), applications in the mobile telephone must be able to recover information stored in the security component of the NFC microchip.
As for any security element, some information stored in the NFC microchip is protected and can be read or modified only after authentication (for example by means of a “triple DES” encryption algorithm). Secret data (for example encryption/decryption keys) and calculation means capable of performing rapidly a cryptographic calculation that can be complex are necessary for effecting such authentication.
The secret data necessary for authentication by the security component of the NFC microchip is stored in the memory of the mobile telephone. Storing this secret data in the mobile telephone and effecting calculations in the mobile telephone (for example by means of a Java® Midlet application using RMS (rights management system) keys), offers the benefit of enhanced security through authentication of the user.
The subscriber smart card of a mobile telephone that has been declared stolen can be disabled, i.e. blocked, by the carrier. However, the mobile telephone could nevertheless be used for near-field (“contactless”) communication with the NFC microchip simply by inserting into the telephone another subscriber smart card that is not blocked.
Consequently, the security and control of the NFC microchip must be improved to guarantee users improved protection in the event of theft or loss of their mobile telephone.